The invention relates to the automatic, or semiautomatic, formation of radius elbow and O.G. set ducts. In the sheet metal trade today, after formation of duct work pieces for radius elbows and O.G. sets, the pieces are edge interlocked together by hand, by a worker running up and down each of the edge configurations to be interlocked, utilizing a power tool, hammer, or the like. Such a method of assembly is relatively time consuming and inefficient, therefore there is the need for a mechanism, and method of operation thereof, which can effect automatic or semiautomatic closure of the edge configurations of radius elbows and O.G. sets. An automatic and a semiautomatic, assembly for the closing of edge configurations of straight duct and transitions is disclosed in my copending application Ser. No. 788,641, filed Apr. 18, 1977 (now U.S. Pat. No. 4,111,143). Heretofore, however, there has been no such arrangement capable of automatic or semiautomatic formation of radius elbows and O.G. sets from duct work pieces.
According to the present invention, a method is provided for formation of radius elbow ducts, and O.G. set ducts, automatically using an edge interlocking machine having automatic edge interlocking components. First, a plurality of duct work pieces are formed out of sheet material, each piece having a predetermined length, and curved edges. At least one of the pieces (and preferably all of the pieces) are formed so that it has an edge configuration adapted to be acted upon to interlock and form a seam with another piece to form the duct. The plurality of pieces are initially placed together to be acted upon by the automatic edge interlocking components, and then the pieces are fed into the edge interlocking components in a general direction H, the automatic edge interlocking components acting on the edge configurations of the pieces to interlock all edge configurations together to form seams of a completed radius elbow, or O.G. set, duct.
The machine according to the present invention for automatically assembling radius elbows and/or O.G. sets comprises a plurality of edge deformation effecting components, each component comprising means for effecting deformation of edge portions of duct work by bending over an upstanding edge portion of an edge configuration. Four edge deformation effecting components preferably are provided, mounted so that they define the corners of a vertical quadrate opening. First mounting means are provided for mounting two of the components at substantially the same vertical height and for movement relative to each other along a horizontal direction P, perpendicular to the horizontal direction of feed H of duct work pieces through the edge interlocking components. A fabrication table is disposed below the two components mounted by the first mounting means, which table extends substantially horizontally and includes a plurality of rollers mounted for rotation about horizontal axes generally parallel to the horizontal direction P; rollers of the fabrication table are disposed on both sides of a vertical plane contaning the first mounting means, so that the duct pieces are supported on either side of the edge inerlocking components. Pivotal mounting means are provided for mounting the components so that they are pivotal about parallel vertical axes with respect to the mounting means therefor. Means are also provided for moving the components relative to each other in the horizontal direction P, and for moving the mounting means to change the vertical position of the mounting means with respect to the fabrication table. The components are movable to a maximum horizontal spacing with respect to each other along the direction P, and the rollers of the fabrication table have a length longer than the maximum horizontal spacing to which the components are movable.
It is a primary object of the present invention to provide for the automatic, or semiautomatic, assemblage of radius elbow and/or O.G. set ducts. This and other objects of the invention will become clear from an inspection of the detailed description of the invention, and from the appended claims.